Nine of 11 hematological patients with disseminated/deep-seated Fusarium infection tested at least twice for Aspergillus galactomannan (GM) had repeated positive results in the absence of Aspergillus isolation in culture. The centrifuged supernatants of 12 Fusarium isolates were tested by a GM enzyme-linked immunosorbent assay (EIA). All the isolates produced positive reactions when tested undiluted. These results show cross-reactivity of Fusarium spp. with Aspergillus GM that may constitute a drawback with respect to the specificity of the Platelia EIA.